Creating a hard soap bar
What can I add to create a harder bar other than limiting the amt. of castor oil I use?
The hardness of the soap depends on the oils that are used in the recipe.
Hard oils will make a hard bar of soap. Try increasing the amount of hard oils in your recipe. Just be careful to not add too much or the recipe may go to trace too quickly in the pot.
Other options include adding a small amount of melted beeswax or stearic acid to the melted oils.
SoapCalc is a great tool to use for designing soap recipes since it shows the qualities the soap will have in its final state.